Endogenous bioactive compounds of naked oats (Avena nuda L.) inhibit α-amylase and α-glucosidase activity

This study aims to investigate the inhibitory effects of free and bound bioactive extracts from naked oat on amylase and glucosidase activity. The free compound extract mainly included kaempferol-3-O-galactoside-6 ''-rhamnoside-3'''-rha, hesperetin-7-O-neohesperidoside, ginsenoside Re and soyasaponin Ba. Ten substances were detected in the bound compound extract, including ferulic acid, oxyacanthine, and trans-4-coumaric acid. The free and bound compound extracts showed dose-dependent inhibitory effects on alpha-amylase and alpha-glucosidase; the inhibition of alpha-amylase was reversible anti-competitive inhibition, and the inhibition of alpha-glucosidase was reversible linear mixed inhibition. The saponin ginsenoside Re had poor inhibitory effects on alpha-amylase and alpha-glucosidase; the saponin soyasaponin Ba had a poor inhibitory effect on alpha-amylase but a good inhibitory effect on alpha-glucosidase. After adding the extracts to the different starches, the hydrolysis rates all decreased significantly (p < 0.05). This study elucidates the low digestibility of naked oats and will help facilitate the development of low-glycemic foods using naked oats.

Automated summary

The free and bound bioactive extracts from naked oat showed inhibitory effects on amylase and glucosidase activity, reducing starch hydrolysis rates significantly. Ginsenoside Re and soyasaponin Ba had different inhibitory effects on amylase and glucosidase.